Rain sensor for detecting rain or other material on window of a vehicle or on other surface

• US 7,752,907 B2
• Filed: 02/27/2009
• Issued: 07/13/2010
• Est. Priority Date: 01/10/2006
• Status: Expired due to Fees

• Current Assignee: Guardian Glass LLC (KOCH Industries Incorporated)
• Original Assignee: Guardian Industries Corporation (KOCH Industries Incorporated)
• Inventors: Veerasamy, Vijayen S.
• Primary Examiner(s): Allen; Andre J
• Application Number:
  US12/379,743
• Publication Number:
  US 20090165550A1
• Time in Patent Office: 501 Days
• Field of Search: 731/701.7, 731/702.1, 701/36, 250/208.1
• US Class Current: 73/170.17
• CPC Class Codes: B32B 17/10036 comprising two outer glass sheets
• CPC Class Codes: B32B 17/10174 Coatings of a metallic or dielectric material on a constituent layer of glass or polymer
• CPC Class Codes: B32B 17/10761 containing vinyl acetal
• CPC Class Codes: B60S 1/0818 including control systems responsive to external conditions, e.g. by detection of moisture, dirt or the like
• CPC Class Codes: B60S 1/0822 characterized by the arrangement or type of detection means
• CPC Class Codes: B60S 1/0825 Capacitive rain sensor
• CPC Class Codes: G06V 20/56 exterior to a vehicle by using sensors mounted on the vehicle

Abstract

A system and/or method for sensing the presence of moisture (e.g., rain) and/or other material(s) on a window such as a vehicle window (e.g., vehicle windshield or backlite). In certain example embodiments, a capacitor-based system and/or method is provided for auto-correlating sensor data to determine the existence of a material on the window, and then cross-correlating sensor data to identify the type and/or amount of that material (e.g., rain). This data may be used to actuate and/or deactivate a vehicle'"'"'s wiper(s), and/or adjust wiper speed. In certain example embodiments, the sensor may include an array of at least two capacitors. In certain example embodiments, the system and/or method may perform check(s) to enhance the accuracy of the detection by comparing, for example, the sign of autocorrelation values, maximum autocorrelation values, and/or gradients of autocorrelation values.

Claims

1. A moisture sensor for sensing the presence of moisture on a vehicle window, the moisture sensor comprising:

at least one capacitor which is affected by moisture present on a surface of the vehicle window;

means for autocorrelating data relating to the capacitor to obtain autocorrelated data, wherein the autocorrelation is used for finding repeating or substantially repeating signal patterns; and

means for determining, based at least on said autocorrelated data, whether moisture is present on the vehicle window.

2. A moisture sensor for sensing the presence of moisture on a vehicle window, the moisture sensor comprising:

at least first and second capacitors which are affected by moisture present on a surface of the vehicle window;

means for cross-correlating data relating to the first and second capacitors so as to correlate data from different capacitors to obtain cross-correlated data; and

means for determining, based at least on said cross-correlated data, a type and/or amount of moisture on the window.

3. A method of sensing the presence of moisture on a vehicle window, the method comprising:

receiving data relating to at least two capacitors supported by the vehicle window;

cross-correlating data relating to the two capacitors so as to correlate data relating to different capacitors to obtain cross-correlated data; and

determining, based at least on said cross-correlated data, a type and/or amount of moisture on the exterior surface of the vehicle window.

4. The method of claim 3, wherein said determining based on at least the cross-correlated data determines the type of moisture on the window, where the type is one or more of:

light rain, heavy rain, fog, sleet, snow, and ice.